1. Field of Invention
This invention generally relates to the acceleration of an object to high velocity by means of successive elastic collisions among an assembly of lower-velocity objects of higher mass, which are kept in linear array, prior to the initiation of the collisions, by a restraining device that permits the axis of the array to be oriented in any desired direction and that allows the assembly of objects to be handled and manipulated as a unit.
2. Cross-Reference to Related Applications
A patent application (Ser. No. 07/713,261, filing date Jun. 11, 1991) entitled "Multiple-Collision Acceleration Demonstrator and Toy," submitted by E. W. Hones, S. A. Colgate and W. G. Hones, also relates generally to acceleration of an object to high velocity by means of successive elastic collisions among an alignment of lower-velocity objects of higher mass. But that invention has the objects suspended in a horizontal line from horizontal supports, with no constraining device, such as in the present application, that allows the assembly of objects to be used as a unit in a vertical alignment or other orientation.
3. Description of Prior Art
The act of accelerating an object to high velocity and/or projecting it long distances or to great heights or with directional precision is a perennial source of human satisfaction, amusement and recreation, and is the basis for most of the countless "ball games" such as baseball, golf, billiards, tennis, etc. In nearly all such cases the object is accelerated by collision with another object and the outcome of the collision is determined by two basic laws of physics--the law of the conservation of energy and the law of the conservation of momentum. A special form of such collisions is found in bouncing objects off a wall, as in handball and racquet ball or off the ground or the floor in games such as basketball or jacks. In these examples the collision occurs between the ball and an object regarded to have infinite mass and still the consequences of the collision obey the two conservation laws mentioned above. The conservation laws tell us that the rebound speed depends on the elastic properties of the ball-surface combination and can range from near zero to very nearly the full speed of impact but it cannot equal or exceed the speed of impact.
The invention described here is yet another "ball game"--one that involves not just a single collision but that, in its preferred embodiment, utilizes a collision, first, between the ground or floor and a constrained linear array of balls, and then multiple collisions among the balls themselves. The device demonstrates a remarkable consequence of the conservation laws-- that, unlike the bouncing of a single ball off the ground or floor in which the bounce speed is always less than the impact speed, the bounce speed of the lightest ball of the linear assembly can be many times the impact speed. The principal of the invention is illustrated in FIG. 1 which shows a series of highly elastic balls (for example steel or polybutadiene) of progressively diminishing size constrained, by a guide-pin through their centers, to lie along a straight line. The guide-pin is fastened in the largest ball while the remaining balls are free to slide along the pin, which, when the balls are all in contact, extends a short distance above the smallest ball. The array is dropped, large ball down. Upon impact with the ground or floor, the impulse is transmitted through the balls giving the smallest ball a high upward velocity which carries it to a large height, much greater than the height to which any of the balls would bounce if dropped singly. The theoretical basis of the invention is further elaborated below.
A patentability search has yielded no prior art against which this invention actually infringes. U.S. Pat. No. 3,002,294 to Jackson (1961), U.S. Patent Des. 217,912 to Trippett (1970) and U.S. Patent Des. 216,999 to Kanbar (1970) are all versions of the long-familiar toy or demonstration device which has a horizontal alignment of suspended steel balls, all of equal mass. Pulling back and releasing one or more balls at one end of the line produces a series of impacts that causes the same number of balls from the other end of the line to rise to approximately the same height to which the first balls were raised. These patents do not address the much different results that are obtained with balls of unequal masses.
U.S. Pat. No. 3,744,472 to O'Ryan (1973) shows a series of two or more "resilient balls" of decreasing size in a vertical array, the largest at the bottom and the smallest at the top, each ball having a socket at its top to receive the ball above. Imparting an upward blow to the bottom ball (as by kicking) causes the smallest ball to depart upward with substantial velocity. That patent describes the balls only in terms of their sizes and "resilience," with no mention made of their weights nor of an important quantity, the coefficient of restitution, which will be defined later in our specification. Thus O'Ryan's "Multiple-Ball and Projectile Toy" is not specified in meaningful, clear, concise, or exact physical terms that would enable a skilled person to produce it. Furthermore, although the O'Ryan device involves transmission of an upward impulse through multiple collisions, it has no constraint that would keep the several balls in linear array if they were to be dropped to impact the ground as in the present invention.